Conductive amorphous oxide contact layers

ABSTRACT

An electronic device is disclosed. The electronic device includes a conductor, and a conductive oxide material electrically connected to the conductor. The conductive oxide materials is substantially amorphous, and the conductive oxide material includes first and second oxide materials. In addition, the first oxide material is different from the second oxide material. The electronic device also includes a second material, electrically connected to the conductive oxide material.

CROSS-REFERENCES TO RELATED APPLICATIONS

This application is a continuation of U.S. application Ser. No.16/546,029, titled “CONDUCTIVE AMORPHOUS OXIDE CONTACT LAYERS,” filedAug. 20, 2019, which is hereby incorporated in its entirety and for allpurposes.

FIELD OF THE INVENTION

The present application generally pertains to conductive amorphous oxidelayers, and more particularly to conductive amorphous oxide layershaving multiple oxide constituents.

BACKGROUND OF THE INVENTION

For various applications, materials having electrical, mechanical,chemical, and other properties are used with varying degrees of costsand benefits. Oxide materials have numerous benefits and are ubiquitousin may applications. Electrically conductive oxide materials having anamorphous or nearly amorphous structure are needed.

BRIEF SUMMARY OF THE INVENTION

One inventive aspect is an electronic device. The electronic deviceincludes a conductor, and a conductive oxide material electricallyconnected to the conductor. The conductive oxide materials issubstantially amorphous, and the conductive oxide material includesfirst and second oxide materials. In addition, the first oxide materialis different from the second oxide material. The electronic device alsoincludes a second material, electrically connected to the conductiveoxide material.

In some embodiments, the first oxide material is conductive, and thesecond oxide material is conductive.

In some embodiments, the first oxide material includes an oxide of anoble metal and the second oxide material includes an oxide of atransition metal.

In some embodiments, the first oxide material has a first crystallinelattice structure and the second oxide material as a second crystallinelattice structure, where the first and second crystalline latticestructures are different.

In some embodiments, the conductive oxide material has a diffusionconstant of oxygen ions less than about 1×10-10 cm2/s.

In some embodiments, the conductive oxide material does not donateoxygen ions to the second material, and the conductive oxide materialdoes not accept oxygen ions from the second material.

In some embodiments, the conductive oxide material is substantiallytransparent.

In some embodiments, the conductive oxide material and the secondmaterial form an ohmic contact therebetween.

In some embodiments, the conductive oxide material and the secondmaterial form a Schottky contact therebetween.

In some embodiments, the conductive oxide material and the conductorform an ohmic contact therebetween.

In some embodiments, the conductive oxide material and the conductorform a Schottky contact therebetween.

In some embodiments, the conductive oxide material and the secondmaterial at least partly form an access device of a memory cell.

Another inventive aspect is a method of forming an electronic device.The method includes connecting a conductive oxide material electricallyto a conductor, where the conductive oxide materials is substantiallyamorphous, and where the conductive oxide material includes first andsecond different oxide materials. The method also includes connecting asecond material to the conductive oxide material.

In some embodiments, the first oxide material is conductive, and thesecond oxide material is conductive.

In some embodiments, the first oxide material includes an oxide of anoble metal and the second oxide material includes an oxide of atransition metal.

In some embodiments, the first oxide material has a first crystallinelattice structure and the second oxide material as a second crystallinelattice structure, where the first and second crystalline latticestructures are different.

In some embodiments, the conductive oxide material has a diffusionconstant of oxygen ions less than about 1×10-10 cm2/s.

In some embodiments, the conductive oxide material does not donateoxygen ions to the second material, and the conductive oxide materialdoes not accept oxygen ions from the second material.

In some embodiments, the conductive oxide material is substantiallytransparent.

In some embodiments, the conductive oxide material and the secondmaterial form an ohmic contact therebetween.

In some embodiments, the conductive oxide material and the secondmaterial form a Schottky contact therebetween.

In some embodiments, the conductive oxide material and the conductorform an ohmic contact therebetween.

In some embodiments, the conductive oxide material and the conductorform a Schottky contact therebetween.

In some embodiments, the conductive oxide material and the secondmaterial at least partly form an access device of a memory cell.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a schematic diagram of an ohmic contact between an oxide and aconductive amorphous oxide material.

FIG. 2 is a schematic diagram of a transistor access device connected toa memory cell.

FIG. 3 is a schematic diagram of a transistor access device connected toa memory cell.

FIG. 4 is a schematic diagram of a Schottky contact between an oxide anda conductive amorphous oxide material.

FIG. 5 is a schematic diagram of an access device connected to a memorycell.

FIG. 6 is a schematic diagram of an access device connected to a memorycell.

FIG. 7 is a schematic diagram of a double contact between an oxide andfirst and second conductive amorphous oxide materials.

FIG. 8 is a schematic diagram of an access device connected to a memorycell.

FIG. 9 is a schematic diagram of an access device connected to a memorycell.

FIG. 10 is a schematic diagram of capacitor.

FIG. 11 is a schematic cross-sectional diagram of a capacitor.

DETAILED DESCRIPTION OF THE INVENTION

Particular embodiments of the invention are illustrated herein inconjunction with the drawings.

Various details are set forth herein as they relate to certainembodiments. However, the invention can also be implemented in wayswhich are different from those described herein. Modifications can bemade to the discussed embodiments by those skilled in the art withoutdeparting from the invention. Therefore, the invention is not limited toparticular embodiments disclosed herein.

Certain oxide materials and their characteristics and attributes arediscussed below. In addition, certain applications of the oxidematerials are described below. Neither the materials nor theapplications thereof are to be limited by this disclosure, as variousalternative materials and applications may be made by those of ordinaryskill in the art in light of and using the features discussed in thisdisclosure.

The oxide materials discussed herein have an amorphous structure formedby at least two different oxides AOx and BOx, where A and B are elementsor groups. One or both of AOx and BOx may be crystalline, however, thecomposite material AOxBOx is a nano level mixture, not a compound, andis amorphous or nearly amorphous or substantially amorphous.

For example, in some embodiments, any crystal grains formed byindividual constituents AOx and BOx are small enough that thesubstantive effect of the composite material AOxBOx in its applicationis as if the composite material AOxBOx were amorphous. For example, thecomposite material AOxBOx may have substantially no ionic conductivity.In some embodiments, the grains of the individual constituents AOx andBOx may be less than about 10 nm, about 9 nm, about 8 nm, about 7 nm,about 6 nm, about 5 nm, about 4 nm, about 3 nm, about 2 nm, about 1 nm,about 0.9 nm, about 0.8 nm, about 0.7 nm, about 0.6 nm, about 0.5 nm,about 0.4 nm, or about 0.3 nm.

Alternatively or additionally, crystal structures of the individualconstituents AOx and BOx may be different. Consequently, adjacent grainsof individual constituents AOx and BOx do not and cannot form acontinuous lattice crystalline structure across their mutual boundary.

Alternatively or additionally, the individual constituents AOx and BOxare mutually insoluble. Therefore, the individual grains of the AOx andBOx constituents contact one another without intermixing.

At least partly because of these properties, when the oxide materialsdiscussed herein are deposited on a substrate, for example with asputtering process, separate phases of the composite material AOxBOx donot or substantially do not form.

A and B elements may, for example, include Ru, Rh, Pd, Re, Ir, Pt, orother noble metals, as understood by those of skill in the art. Forexample, some other metals having low affinity for oxygen as compared toyet other metals are considered noble metals by those of skill in theart. A and B elements may, for example, include Ti, Zr, Hf, Nb, Ta, Si,Al, Ga, or other transition metals, as understood by those of skill inthe art. For example, some other elements are considered transitionmetals by those of skill in the art.

In some embodiments, other elements or groups are used to form the AOxor BOx constituents. For example, other similar elements or groups areused to form the AOx or BOx constituents.

In some embodiments, the AOx and BOx constituents are both conductive.In some embodiments, one of the AOx and BOx constituents is conductive.In such embodiments, the conductive constituent forms conductive one ormore paths through the AOxBOx composite material.

All combinations of the AOx and BOx individual constituents arecontemplated and included herein as embodiments of the compositematerial AOxBOx. In addition, composite materials AOxBOx having anycombination of the properties discussed herein are contemplated andincluded herein as embodiments.

In some embodiments, the AOxBOx composite material is conductive orsubstantially conductive. For example, the AOxBOx composite material mayhave resistivity less than 1×10⁻³ Ohm-cm.

In some embodiments, the AOxBOx composite material is transparent orsubstantially transparent to a bandwidth of electromagnetic radiation.For example, the AOxBOx composite material may absorb less than 10% ofvisible light transmitted therethrough.

In some embodiments, the AOxBOx composite material is opaque orsubstantially opaque to a bandwidth of electromagnetic radiation.

In some embodiments, the AOxBOx composite material is fully oxidized orsubstantially fully oxidized. Accordingly, when in contact with anothermaterial the AOxBOx composite material does not donate to or acceptoxygen ions from the other material. For example, the amount, if any, ofoxygen ions which migrate from the other material to the AOxBOxcomposite material causes no substantial difference in one or more ofthe electrical, mechanical, and chemical behavior of the other material.

In some embodiments, the AOxBOx composite material prevents orsubstantially prevents oxygen ion conduction therethrough. For example,the diffusion constant of oxygen ions may be less than about 1×10⁻¹⁰cm²/s, less than about 1×10⁻¹¹ cm²/s, or less than about 1×10⁻¹² cm²/s.

In some embodiments, the AOxBOx composite material may be deposited on asubstrate at temperatures sufficiently low that the material does notchemically react with the substrate. For example, the AOxBOx compositematerial may be deposited at room temperature or at about roomtemperature.

Accordingly, in some embodiments, when the AOxBOx composite material isdeposited, the AOxBOx composite material does not donate or acceptoxygen to or from the substrate material. As a result, the properties ofthe substrate material significant for the application, as understood bythose of skill in the art, are not altered by the presence, proximity,or contact of the AOxBOx composite material. For example, the amount, ifany, of oxygen ions which migrate to or from the substrate material fromor to the AOxBOx composite material causes no substantial difference inone or more of the electrical, mechanical, and chemical behavior of thesubstrate material or of the AOxBOx composite material. In someembodiments, no or substantially no transition layer is formed.

In some embodiments, the AOxBOx composite material may be deposited on asubstrate with a reactive sputtering process. A single target comprisingboth A and B elements or groups may be used in an atmosphere comprisingoxygen. Alternatively, a first target comprising the A element or groupand a second target comprising the B element or group may be used in theatmosphere comprising oxygen.

The temperature during the deposition may be, for example, about roomtemperature. Higher temperatures may also be used. For example,temperatures less than about 50 C., about 100 C., about 150 C., about200 C., about 250 C., or about 300 C. may be used.

The deposition pressure may be, for example, about 0.1 m Torr, about 10m Torr, or between about 0.1 m Torr and about 10 m Torr.

During the deposition, the oxygen partial pressure may be, for example,about 2%, about 20%, or between about 2% and about 20%.

During the deposition, the RF power may be, for example, about 0.1W/cm², about 10 W/cm², or between about 0.1 W/cm² and about 10 W/cm².

Other deposition processes may be used, as understood by those of skillin the art. For example, any of the following processes may be used:Pulsed Laser deposition, Chemical Vapor deposition, Molecular BeamEpitaxy deposition, and Atomic Layer deposition. In some embodiments,solution deposition techniques may be used, such as Sol-gel andMetal-Organic deposition. As understood by those of ordinary skill inthe art, other deposition techniques may be used.

In some applications, an AOxBOx material is formed on a substrate tocreate an electrical contact between the AOxBOx material and thesubstrate material. In some embodiments, the contact is Ohmic orsubstantially Ohmic. In some embodiments, the contact forms a Schottkybarrier. As understood by those of skill in the art, the A and Belements or groups used for the AOxBOx material, the specificconstitution of the AOxBOx material, and the material of the substratedetermine whether the contact is Ohmic, substantially Ohmic, or forms aSchottky barrier.

FIG. 1 is a schematic diagram of an ohmic contact between a material 120and a conductive amorphous AOxBOx material 110. The contact betweenmaterial 120 and AOxBOx material 110 forms an ohmic contact havingproperties of ohmic contacts, as understood by those of skill in theart. FIG. 1 illustrates an embodiment of a particular application of acontact formed with AOxBOx materials. Numerous other applications arealso contemplated. Some, but not all of these other applications arediscussed elsewhere herein.

For example, the ohmic contact may have current vs. voltage linearityproperties identifiable by one of skill in the art as beingcharacteristic of an ohmic contact. In some embodiments, the ohmiccontact is non-rectifying, and may be characterized by a linear orsubstantially linear current vs. voltage curve. The ohmic contact mayhave low resistivity. For example, the contact may have a contactresistance which is less than about 1e-11 Ohm m², about 1e-12 Ohm m²,about 1e-13 Ohm m², or about 1e-14 Ohm m². The contact, may, forexample, be identified as being ohmic by one of skill in the art as aresult of parameters of the material 120 and AOxBOx material 110, suchas Fermi level being substantially equal.

In any embodiment or application, a noble metal layer may be formedbetween the material 120 and the AOxBOx material 110. In suchembodiments or applications, a first ohmic contact may be formed betweenthe AOxBOx material 110 and the noble metal layer. Additionally oralternatively, a second ohmic contact may be formed between the material120 and the noble metal layer.

The material 120 may, for example, comprise a conductive oxide. Forexample, material 120 may comprise one or more of: InO_(x), ZnO,GaO_(x), SnO_(x), (InGa)O_(x), (ZnGa)O_(x), (InZnGa)O_(x), BaSnO₃, andITO, as understood by those of skill in the art. Other conductiveoxides, as understood by those of skill in the art, may be used.

The material 120 may comprise a semiconductor or semiconducting oxide,for example, having a conductivity which may be electrically,chemically, or mechanically controlled or modified, as understood bythose of skill in the art. For example, material 120 may comprise one ormore of: InO_(x), ZnO, GaO_(x), SnO_(x), (InGa)O_(x), (ZnGa)O_(x),(InZnGa)O_(x), GaN, AIN as understood by those of skill in the art.Other semiconductors and semiconductor oxides, as understood by those ofskill in the art, may be used.

The material 120 may comprise an insulative oxide. For example, material120 may comprise one or more of: ZrO₂, doped ZrO₂, BaTiO₃, SrTiO₃, asunderstood by those of skill in the art. Other insulative oxides, asunderstood by those of skill in the art, may be used.

The material 120 may comprise a non-oxide conductive metal material. Forexample, material 120 may comprise one or more of: Al, Pt, Cu, Au, Ag,W, Ti, and Ta, as understood by those of skill in the art. Othernon-oxide conductive metal materials, as understood by those of skill inthe art, may be used.

The material 120 may comprise a non-oxide conductive noble metalmaterial. For example, material 120 may comprise one or more of: Ru, Rh,Pd, Ag, Os, Ir, Pt, and Au, as understood by those of skill in the art.Other non-oxide conductive noble metal materials, as understood by thoseof skill in the art, may be used.

The material 120 may comprise another non-oxide conductive material. Forexample, material 120 may comprise one or more of: TiN, TaN, TiAlN_(x),and TaAlN_(x), as understood by those of skill in the art. Othernon-oxide conductive materials, as understood by those of skill in theart, may be used.

The material 120 may comprise a oxide or non-oxide semiconductormaterial, for example, having a conductivity which may be electrically,chemically, or mechanically controlled or modified, as understood bythose of skill in the art. For example, material 120 may comprise one ormore of: or (PrCa)MnO₃, (Sm_(1-x)Ca_(x))MnO₃, and (La_(1-x)Sr_(x))MnO₃,GaN, AIN as understood by those of skill in the art. Other non-oxidesemiconductor materials, as understood by those of skill in the art, maybe used.

The material 120 may comprise a non-oxide insulative material. Forexample, material 120 may comprise one or more of: SiO₂, and Ta₂O₅, asunderstood by those of skill in the art. Other non-oxide insulativematerials, as understood by those of skill in the art, may be used.

Material 120 may be a single material, multiple materials, or may be asolid solution of multiple materials.

The AOxBOx material 110 may have any of the properties of the AOxBOxmaterials discussed elsewhere herein.

FIG. 2 is a schematic diagram of a transistor access device 210connected to a memory cell 220 of a memory device. FIG. 2 illustrates anembodiment of a particular application of a contact formed with AOxBOxmaterials. Numerous other applications are also contemplated. Some, butnot all of these other applications are discussed elsewhere herein.

In this embodiment, access device 210 is connected to a ground potentialby a first AOxBOx contact structure 230, is connected to a word line ofthe memory device by a second AOxBOx contact structure 240, and isconnected to the memory cell 220 by a third AOxBOx contact structure250. In addition, the memory cell 220 is connected to a bit line of thememory device by a fourth AOxBOx contact structure 260.

FIG. 3 is a schematic cross-sectional diagram of a transistor accessdevice 310 connected to a memory cell 320, such as that illustrate inFIG. 2 . FIG. 3 illustrates an embodiment of a particular application ofa contact formed with AOxBOx materials. Numerous other applications arealso contemplated. Some, but not all of these other applications arediscussed elsewhere herein.

Access device 310 includes substrate 300, drain and source 322, and gate323, which, for example, may include a gate oxide and a conductor. Theconductor may comprise any conductive material listed herein or asunderstood by those of skill in the art. The drain and source 322 maycomprise any conductive or semiconductive material listed herein or asunderstood by those of skill in the art. In some embodiments, the drainand source 322 are semiconductor oxides.

In this embodiment, access device 310 includes plug contacts 325 whichare separated by insulators 324. Plug contacts 325 may, for example,comprise tungsten (W). As understood by those of skill in the art, otherplug contact materials may be used.

The source 322 of access device 310 is connected to a ground potentialconductor 332 through source plug contact 325 by a first AOxBOx contactstructure 330. Conductor 332 may comprise any conductive material listedherein or as understood by those of skill in the art. AOxBOx contactstructure 330 may have any of the properties of the AOxBOx materialsdiscussed elsewhere herein. AOxBOx contact structure 330 may form anohmic contact with the source plug contact 325 connected thereto.Additionally or alternatively, AOxBOx contact structure 330 may form anohmic contact with the conductor 332.

In alternative embodiments, source plug contact 325 is omitted. In suchembodiments, AOxBOx contact structure 330 forms a contact with thesource 322. The contact between AOxBOx contact structure 330 and thesource 322 may be ohmic. In some embodiments, source 322 is formed of anoxide material, such as a semiconductor oxide material.

The gate 323 of access device 310 is connected to a gate conductor 342through gate plug contact 325 by a second AOxBOx contact structure 340.Conductor 342 may comprise any conductive material listed herein or asunderstood by those of skill in the art. AOxBOx contact structure 340may have any of the properties of the AOxBOx materials discussedelsewhere herein. AOxBOx contact structure 340 may form an ohmic contactwith the gate plug contact 325 connected thereto. Additionally oralternatively, AOxBOx contact structure 340 may form an ohmic contactwith the conductor 342.

In alternative embodiments, gate plug contact 325 is omitted. In suchembodiments, AOxBOx contact structure 340 forms a contact with theconductor of the gate 323. The contact between AOxBOx contact structure340 and the conductor of the gate 323 may be ohmic. In some embodiments,the conductor of the gate 323 is formed of an oxide material, such as asemiconductor oxide material.

In alternative embodiments, gate plug contact 325 and gate 323 areomitted. In such embodiments, AOxBOx contact structure 340 forms acontact with the channel portion 321 of access device 310. The contactbetween AOxBOx contact structure 340 and the channel portion 321 may bea Schottky barrier contact, having characteristics similar or identicalto those of any of the Schottky barriers or Schottky diodes discussedelsewhere herein. The Schottky barrier contact may form a Schottky diodehaving a polarity or orientation such that a voltage placed across theAOxBOx contact structure 340 and source 322 which causes the channelportion 321 to conduct also causes the Schottky diode to be reversebiased.

The drain 322 of access device 310 is connected to the memory cell 320through drain plug contact 325 by a third AOxBOx contact structure 350.AOxBOx contact structure 350 may have any of the properties of theAOxBOx materials discussed elsewhere herein. AOxBOx contact structure350 may form an ohmic contact with the drain plug contact 325 connectedthereto. Additionally or alternatively, AOxBOx contact structure 350 mayform an ohmic contact with the memory cell 320.

Memory cell 320 may comprise a memory layer material, such as PCMO, oranother memory layer material and an electrode layer, as understood bythose of skill in the art. The electrode layer may, for example,comprise tungsten, and may cooperatively form a metal oxideheterojunction memory with the memory layer material. The electrodelayer may be configured to accept or donate oxygen ions or vacanciesfrom or to memory layer material in response to an electric fieldapplied across the electrode layer and the memory layer material. Insome embodiments, the electrode layer may be oxygen-rich and maycooperatively form an oxygen ion heterojunction memory cell with memorylayer material. In alternative embodiments, the electrode layer may beoxygen depleted and may cooperatively form an oxygen vacancyheterojunction memory cell with the memory layer material. As understoodin the art, the memory cell may include additional layers. In someembodiments the memory cell 320 includes one or more additional AOxBOxcontact layers.

As understood by those of skill in the art, the resistivity of thememory layer material is dependent on the concentration of oxygen ionsor vacancies therein. Therefore, memory cell 320 functions as arewritable memory cell, where the state of the memory cell 320corresponds with the resistivity of the memory layer material. Thememory layer material is written by applying a voltage to induce anelectric field to force the concentration of the oxygen ions orvacancies to a desired concentration state, and the desiredconcentration state corresponds with a desired resistivity state. As aresult, the resistance of the memory layer material is programmed by thewrite operation. To read the state of the memory cell, a voltage or acurrent may be applied to the memory cell 320. A current or voltagegenerated in response to the applied voltage or current is dependent onthe resistance state of the memory cell material, and may be sensed todetermine the resistance state.

In alternative embodiments, drain plug contact 325 is omitted. In suchembodiments, AOxBOx contact structure 350 forms a contact with the drain322. The contact between AOxBOx contact structure 350 and the drain 322may be ohmic. In some embodiments, drain contact 325 is formed of anoxide material, such as a semiconductor oxide material.

Accordingly, in some embodiments, AOxBOx contact structures may be usedfor ohmic contacts to source and drain contacts for an oxidesemiconductor transistor. Additionally or alternatively, a AOxBOxcontact structure may be used to create a Schottky diode gate contactfor the oxide semiconductor transistor. The Schottky barrier contact mayform a Schottky diode having a polarity or orientation such that avoltage placed across the AOxBOx contact structure and source whichcauses the channel to conduct also causes the Schottky diode to bereversed biased. The Schottky barrier contact may have property similaror identical to those Schottky barriers and Schottky diodes discussedelsewhere herein.

The memory cell 320 of access device 310 is connected to a conductor 362by a first AOxBOx contact structure 360. Conductor 362 may comprise anyconductive material listed herein or as understood by those of skill inthe art. AOxBOx contact structure 360 may have any of the properties ofthe AOxBOx materials discussed elsewhere herein. AOxBOx contactstructure 360 may form an ohmic contact with the source plug contact 325connected thereto. Additionally or alternatively, AOxBOx contactstructure 360 may form an ohmic contact with the conductor 362.

FIG. 4 is a schematic diagram of a Schottky contact between a material420 and a conductive amorphous AOxBOx material 410. The contact betweenmaterial 420 and AOxBOx material 410 forms a Schottky barrier contacthaving properties of Schottky barriers or diodes, as understood by thoseof skill in the art. The Schottky barrier may, for example, have abarrier height of between about 0.3 eV and about 2.5 eV. In someembodiments, the barrier height may be greater than or less than thisrange.

FIG. 4 illustrates an embodiment of a particular application of acontact formed with AOxBOx materials. Numerous other applications arealso contemplated. Some, but not all of these other applications arediscussed elsewhere herein.

For example, the Schottky contact may have current vs. voltageproperties identifiable by one of skill in the art as beingcharacteristic of a Schottky contact. For example, the Schottky contactmay be rectifying. The Schottky contact may have low resistivity forcurrent flowing from anode to cathode. The contact, may, for example, beidentified as being Schottky by one of skill in the art as having aSchottky barrier as a result of parameters of the material 420 andAOxBOx material 410, such as Fermi level and Fermi level pinning, asunderstood by those of skill in the art.

The material 420 may, for example, comprise any of the materialsdiscussed above with reference to material 120. The material 420 mayhave properties and characteristics similar or identical to material120, discussed above.

The AOxBOx material 410 may have any of the properties of the AOxBOxmaterials discussed elsewhere herein.

In any embodiment or application, a noble metal layer may be formedbetween the material 420 and the AOxBOx material 410. In suchembodiments or applications, the material 420/noble metal/AOxBOxmaterial 410 stack effectively forms a Schottky barrier. In someembodiments, the Schottky barrier is formed between the noble metal andthe AOxBOx material 410.

FIG. 5 is a schematic diagram of an access device 510 connected to amemory cell 520 of a memory device. Memory cell 520 may, for example, bea unipolar device, for example, where set and reset operations areperformed with the same voltage polarity across the memory cell 520. Inthis embodiment, access device 510 comprises a diode. FIG. 5 illustratesan embodiment of a particular application of a contact formed withAOxBOx materials. Numerous other applications are also contemplated.Some, but not all of these other applications are discussed elsewhereherein.

In this embodiment, access device 510 is connected to a word line of thememory device by a first AOxBOx contact structure 530, and is connectedto the memory cell 520 by a second AOxBOx contact structure 540. Inaddition, the memory cell 520 is connected to a bit line of the memorydevice by a third AOxBOx contact structure 550.

FIG. 6 is a schematic cross-sectional diagram of a memory cell 620connected to a diode access device, for example, such as access device510 of FIG. 5 . The diode access device includes first AOxBOx contactstructure 610 and material 615. The diode access device includes aSchottky contact between material 615 and AOxBOx contact structure 610.

FIG. 6 illustrates an embodiment of a particular application of acontact formed with AOxBOx materials. Numerous other applications arealso contemplated. Some, but not all of these other applications arediscussed elsewhere herein.

Material 615 may have characteristics similar or identical any of thecharacteristics of material 120, discussed above with reference to FIG.1 . First AOxBOx contact structure 610 may have any of the properties ofthe AOxBOx materials discussed elsewhere herein.

The first AOxBOx contact structure 610 of the diode access device isconnected to a word line conductor 605 of the memory device. The AOxBOxcontact structure 610 and word line conductor 605 may form an ohmiccontact. Word line conductor 605 may comprise any conductive materiallisted herein or as understood by those of skill in the art, and mayfunction as a word line in the memory device as understood by those ofskill in the art.

The AOxBOx contact structure 610 of the diode access device is alsoconnected to material 615 and forms a Schottky diode therewith. In thisembodiment, the cathode of the Schottky diode is formed by the AOxBOxcontact structure 610, and the anode of the Schottky diode is formed bythe material 615.

Material 615 of the diode access device is also connected to the memorycell 620 by a second AOxBOx contact structure 640. Second AOxBOx contactstructure 640 may have any of the properties of the AOxBOx materialsdiscussed elsewhere herein. Second AOxBOx contact structure 640 may forman ohmic contact with material 615. Second AOxBOx contact structure 640may also form an ohmic contact with the memory cell 620.

In alternative embodiments, second AOxBOx contact structure 640 forms aSchottky contact with the memory cell 620, where the cathode of theresulting Schottky diode is formed by the second AOxBOx contactstructure 640, and the anode of the Schottky diode is formed by thememory cell 620, or a portion of the memory cell 620 contacting thesecond AOxBOx contact structure 640. In such embodiments, the firstAOxBOx contact structure 610, and the material 615 may be omitted. Inaddition, in such embodiments, second AOxBOx contact structure 640 mayform an ohmic contact with the word line conductor 605.

Memory cell 620 may comprise a memory layer material, such as PCMO, oranother memory layer material and an electrode layer, as understood bythose of skill in the art. The electrode layer may, for example,comprise tungsten, and may cooperatively form a metal oxideheterojunction memory with the memory layer material. The electrodelayer may be configured to accept or donate oxygen ions or vacanciesfrom or to memory layer material in response to an electric fieldapplied across the electrode layer and the memory layer material. Insome embodiments, the electrode layer may be oxygen-rich and maycooperatively form an oxygen ion heterojunction memory cell with memorylayer material. In alternative embodiments, the electrode layer may beoxygen depleted and may cooperatively form an oxygen vacancyheterojunction memory cell with the memory layer material. As understoodin the art, the memory cell may include additional layers. In someembodiments the memory cell 620 includes one or more additional AOxBOxcontact layers.

As understood by those of skill in the art, the resistivity of thememory layer material is dependent on the concentration of oxygen ionsor vacancies therein. Therefore, memory cell 620 functions as arewritable memory cell, where the state of the memory cell 620corresponds with the resistivity of the memory layer material. Thememory layer material is written by applying a voltage to induce anelectric field to force the concentration of the oxygen ions orvacancies to a desired concentration state, and the desiredconcentration state corresponds with a desired resistivity state. As aresult, the resistance of the memory layer material is programmed by thewrite operation. To read the state of the memory cell, a voltage or acurrent may be applied to the memory cell 620. A current or voltagegenerated in response to the applied voltage or current is dependent onthe resistance state of the memory cell material, and may be sensed todetermine the resistance state.

The memory cell 620 is connected to a bit line conductor 660 of thememory device by a third AOxBOx contact structure 650. Third AOxBOxcontact structure 650 may have any of the properties of the AOxBOxmaterials discussed elsewhere herein. Third AOxBOx contact structure 660may form an ohmic contact with the memory cell 620. Third AOxBOx contactstructure 650 may also form an ohmic contact with bit line conductor660. Bit line conductor 660 may comprise any conductive material listedherein or as understood by those of skill in the art, and may functionas a bit line in the memory device as understood by those of skill inthe art.

FIG. 7 is a schematic cross-sectional diagram of a double contactbetween a material 720 and first and second conductive amorphous AOxBOxmaterials 710 and 730. The contact between material 720 and first AOxBOxmaterial 710 may form a Schottky barrier contact having properties suchas those discussed elsewhere herein. The contact between material 720and first AOxBOx material 710 may form an ohmic having properties suchas those discussed elsewhere herein. The contact between material 720and second AOxBOx material 730 may form a Schottky barrier contacthaving properties such as those discussed elsewhere herein. The contactbetween material 720 and second AOxBOx material 730 may form an ohmichaving properties such as those discussed elsewhere herein.

FIG. 7 illustrates an embodiment of a particular application of acontact formed with AOxBOx materials. Numerous other applications arealso contemplated. Some, but not all of these other applications arediscussed elsewhere herein.

The material 720 may, for example, comprise any of the materialsdiscussed above with reference to material 120. The material 420 mayhave properties and characteristics similar or identical to material120, discussed above.

The first and second AOxBOx materials 710 and 730 may have any of theproperties of the AOxBOx materials discussed elsewhere herein. In someembodiments, the first and second AOxBOx materials 710 and 730 comprisethe same AOxBOx material. In some embodiments, the first and secondAOxBOx materials 710 and 730 comprise different AOxBOx materials.

In any embodiment or application, a noble metal layer may be formedbetween the material 720 and either of the AOxBOx materials 710 and 730.

FIG. 8 is a schematic diagram of an access device 810 connected to amemory cell 820 of a memory device. In this embodiment, access device810 comprises back to back diodes. FIG. 8 illustrates an embodiment of aparticular application of a contact formed with AOxBOx materials.Numerous other applications are also contemplated. Some, but not all ofthese other applications are discussed elsewhere herein.

In this embodiment, back to back diode access device 810 is connected toa word line of the memory device by a first AOxBOx contact structure830, and is connected to the memory cell 820 by a second AOxBOx contactstructure 840. In addition, the memory cell 820 is connected to a bitline of the memory device by a third AOxBOx contact structure 850.

FIG. 9 is a schematic cross-sectional diagram of a memory cell 920connected to a back to back diode access device, for example, such asaccess device 810 of FIG. 8 . The back to back diode access deviceincludes first and second AOxBOx contact structures 910 and 930, andmaterial 915. The back to back diode access device includes a firstSchottky contact between material 915 and first AOxBOx contact structure910 and a second Schottky contact between material 915 and second AOxBOxcontact structure 930.

FIG. 9 illustrates an embodiment of a particular application of acontact formed with AOxBOx materials. Numerous other applications arealso contemplated. Some, but not all of these other applications arediscussed elsewhere herein.

Material 915 may have characteristics similar or identical any of thecharacteristics of material 120, discussed above with reference to FIG.1 . First and second AOxBOx contact structure 910 and 930 may have anyof the properties of the AOxBOx materials discussed elsewhere herein.

The first AOxBOx contact structure 910 of the diode access device isconnected to a word line conductor 905 of the memory device. The firstAOxBOx contact structure 910 and word line conductor 905 may form anohmic contact. Word line conductor 905 may comprise any conductivematerial listed herein or as understood by those of skill in the art,and may function as a word line in the memory device as understood bythose of skill in the art.

The AOxBOx contact structure 910 of the diode access device is alsoconnected to material 915 and forms a first Schottky contact of a firstSchottky diode. In this embodiment, the cathode of the first Schottkydiode is formed by the first AOxBOx contact structure 910, and the anodeof the first Schottky diode is formed by the material 915.

The material 915 of the diode access device is also connected to thememory cell 920 by a second AOxBOx contact structure 940. Second AOxBOxcontact structure 940 may have any of the properties of the AOxBOxmaterials discussed elsewhere herein. Second AOxBOx contact structure940 may form an second Schottky contact with material 915. In thisembodiment, the cathode of the first Schottky diode is formed by thesecond AOxBOx contact structure 940, and the anode of the secondSchottky diode is formed by the material 915.

In alternative embodiments, second AOxBOx contact structure 940 forms aSchottky contact with the memory cell 920, where the anode of theresulting Schottky diode is formed by the second AOxBOx contactstructure 940, and the cathode of the Schottky diode is formed by thememory cell 920, or a portion of the memory cell 920 contacting thesecond AOxBOx contact structure 940. In such embodiments, the firstAOxBOx contact structure 910, and the material 915 may be omitted. Inaddition, in such embodiments, second AOxBOx contact structure 640 mayform a Schottky contact with the word line conductor 905, where theanode of the resulting Schottky diode is formed by the second AOxBOxcontact structure 940, and the cathode of the Schottky diode is formedby the word line conductor 905.

Memory cell 920 may comprise a memory layer material, such as PCMO, oranother memory layer material and an electrode layer, as understood bythose of skill in the art. The electrode layer may, for example,comprise tungsten, and may cooperatively form a metal oxideheterojunction memory with the memory layer material. The electrodelayer may be configured to accept or donate oxygen ions or vacanciesfrom or to memory layer material in response to an electric fieldapplied across the electrode layer and the memory layer material. Insome embodiments, the electrode layer may be oxygen-rich and maycooperatively form an oxygen ion heterojunction memory cell with memorylayer material. In alternative embodiments, the electrode layer may beoxygen depleted and may cooperatively form an oxygen vacancyheterojunction memory cell with the memory layer material. As understoodin the art, the memory cell may include additional layers. In someembodiments the memory cell 920 includes one or more additional AOxBOxcontact layers.

As understood by those of skill in the art, the resistivity of thememory layer material is dependent on the concentration of oxygen ionsor vacancies therein. Therefore, memory cell 920 functions as arewritable memory cell, where the state of the memory cell 920corresponds with the resistivity of the memory layer material. Thememory layer material is written by applying a voltage to induce anelectric field to force the concentration of the oxygen ions orvacancies to a desired concentration state, and the desiredconcentration state corresponds with a desired resistivity state. As aresult, the resistance of the memory layer material is programmed by thewrite operation. To read the state of the memory cell, a voltage or acurrent may be applied to the memory cell 920. A current or voltagegenerated in response to the applied voltage or current is dependent onthe resistance state of the memory cell material, and may be sensed todetermine the resistance state.

The memory cell 920 is connected to a bit line conductor 960 of thememory device by a third AOxBOx contact structure 950. Third AOxBOxcontact structure 950 may have any of the properties of the AOxBOxmaterials discussed elsewhere herein. Third AOxBOx contact structure 960may form an ohmic contact with the memory cell 920. Third AOxBOx contactstructure 950 may also form an ohmic contact with bit line conductor960. Bit line conductor 960 may comprise any conductive material listedherein or as understood by those of skill in the art, and may functionas a bit line in the memory device as understood by those of skill inthe art.

FIG. 10 is a schematic diagram of capacitor 1000 formed by a doublecontact between a material and first and second conductive amorphousAOxBOx materials. FIG. 10 illustrates an embodiment of a particularapplication of a contact formed with AOxBOx materials. Numerous otherapplications are also contemplated. Some, but not all of these otherapplications are discussed elsewhere herein.

In this embodiment, capacitor 1000 is connected to a first conductor ofa device by a first AOxBOx contact structure 1030, and is connected to asecond conductor of the device by a second AOxBOx contact structure1040.

FIG. 11 is a schematic cross-sectional diagram of a capacitor 1100, suchas capacitor 1000 of FIG. 10 . Capacitor 1000 includes first and secondAOxBOx contact structures 1110 and 1130, and material 1115. Thecapacitor 1100 includes a first contact between material 1115 and firstAOxBOx contact structure 1110 and a second contact between material 1115and second AOxBOx contact structure 1130. Material 1115 may havecharacteristics similar or identical any of the characteristics of theinsulative embodiments of material 120, discussed above with referenceto FIG. 1 . First and second AOxBOx contact structure 1110 and 1130 mayhave any of the properties of the AOxBOx materials discussed elsewhereherein.

FIG. 11 illustrates an embodiment of a particular application of acontact formed with AOxBOx materials. Numerous other applications arealso contemplated. Some, but not all of these other applications arediscussed elsewhere herein.

The first AOxBOx contact structure 1110 is connected to a conductor 1105of a device. The first AOxBOx contact structure 1110 and conductor 1105may form an ohmic contact.

The first AOxBOx contact structure 1110 is also connected to material1115. In addition, material 1115 is connected to the second AOxBOxcontact structure 1130. The first AOxBOx contact structure 1110/material1115/second AOxBOx contact structure 1130 stack forms a two platecapacitor having capacitance properties resulting from, for example, thethickness and dielectric constant of material 1115.

In addition, the second AOxBOx contact structure 1130 is connected to aconductor 1160 of the device. The second AOxBOx contact structure 1130and conductor 1160 may form an ohmic contact.

Though the present invention is disclosed by way of specific embodimentsas described above, those embodiments are not intended to limit thepresent invention. Based on the methods and the technical aspectsdisclosed herein, variations and changes may be made to the presentedembodiments by those of skill in the art without departing from thespirit and the scope of the present invention.

What is claimed is:
 1. An electronic device, comprising: a conductor; aconductive oxide material electrically connected to the conductor,wherein the conductive oxide material comprises a mixture of first andsecond oxide materials, wherein the first oxide material is conductive,and wherein the second oxide material is insulative; and a secondmaterial, electrically connected to the conductive oxide material,wherein the conductive oxide material is substantially nanocrystalline,and wherein the first oxide material has a first crystalline latticestructure and the second oxide material has a second crystalline latticestructure, wherein the first and second crystalline lattice structuresare different.
 2. The electronic device of claim 1, wherein the firstand second oxide materials each comprise crystal grains having a grainsize less than about 10 nm.
 3. The electronic device of claim 1, whereinthe conductive oxide material has a diffusion constant of oxygen ionsless than about 1×10-10 cm2/s.
 4. The electronic device of claim 1,wherein the conductive oxide material does not donate oxygen ions to thesecond material, and wherein the conductive oxide material does notaccept oxygen ions from the second material.
 5. The electronic device ofclaim 1, wherein the conductive oxide material is substantiallytransparent.
 6. The electronic device of claim 1, wherein at least oneof: the conductive oxide material and the second material form an ohmiccontact therebetween, and the conductive oxide material and theconductor form an ohmic contact therebetween.
 7. The electronic deviceof claim 1, wherein at least one of: the conductive oxide material andthe second material form a Schottky contact therebetween, and theconductive oxide material and the conductor form a Schottky contacttherebetween.
 8. The electronic device of claim 1, wherein theconductive oxide material and the second material at least partly forman access device of a memory cell.
 9. The electronic device of claim 1,wherein the second material forms a source or drain of a transistor. 10.A method of forming an electronic device, the method comprising:connecting a conductive oxide material electrically to a conductor,wherein the conductive oxide material comprises a mixture of first andsecond oxide materials wherein the first oxide material is conductive,and wherein the second oxide material is insulative; and connecting asecond material to the conductive oxide material, wherein the conductiveoxide material is substantially nanocrystalline, and wherein the firstoxide material has a first crystalline lattice structure and the secondoxide material has a second crystalline lattice structure, wherein thefirst and second crystalline lattice structures are different.
 11. Themethod of claim 10, wherein the first and second oxide materials eachcomprise crystal grains having a grain size less than about 10 nm. 12.The method of claim 10, wherein the conductive oxide material has adiffusion constant of oxygen ions less than about 1×10-10 cm2/s.
 13. Themethod of claim 10, wherein the conductive oxide material does notdonate oxygen ions to the second material, and wherein the conductiveoxide material does not accept oxygen ions from the second material. 14.The method of claim 10, wherein the conductive oxide material issubstantially transparent.
 15. The method of claim 10, wherein at leastone of: the conductive oxide material and the second material form anohmic contact therebetween, and the conductive oxide material and theconductor form an ohmic contact therebetween.
 16. The method of claim10, wherein at least one of: the conductive oxide material and thesecond material form a Schottky contact therebetween, and the conductiveoxide material and the conductor form a Schottky contact therebetween.17. The method of claim 10, wherein the conductive oxide material andthe second material at least partly form an access device of a memorycell.
 18. The method of claim 10, wherein the second material forms asource or drain of a transistor.